1. Field of the Invention
This invention relates generally to electrical connectors, and more particularly to a spark plug connector which is adjustable in order to obtain a desired angle between a spark ignition wire and an associated spark plug.
2. Description of the Prior Art
A long recognized problem encountered with internal combustion engines such as used in motor vehicles, and the like, is that the wires which transmit an electrical impulse to a spark plug in a predetermined sequence must lie in a certain relationship with respect to an associated spark plug in order to insure a good electrical connection between the wire and plug. The conventional solution to this problem is to supply the spark plug ignition wire for a particular engine as part of a set of wires of predetermined varying sizes provided with a respective connector of an appropriate angle for a specific plug. This arrangement results in the necessity of a relatively large number of different sets of ignition wires to be kept in stock by auto parts distributors, dealers, and the like.
It has been recognized that the aforementioned problem could be overcome by providing spark plug connectors which permit the ignition wire to be connected to an associated spark plug at a variable angle so as to permit a proper connection between the wire and plug regardless of the position and orientation of the plug. In this manner, a given set of spark plug ignition wires can be used with a large number of engines. An example of a variable angle spark plug connector can be found in U.S. Pat. No. 3,354,419, issued Nov. 21, 1967, to L. E. Miller, Jr., wherein the portion of the connector which receives the associated spark plug is pivotally mounted to a further portion of the connector which is electrically attached to an ignition wire. The two portions are rotatably joined to one another as by a rivet so as to permit their relative movement either between an axial and right angle orientation, or between a 0.degree. and a 180.degree. relationship. A major disadvantage with the various embodiments set forth in this construction, however, is that no structure is provided for retaining the two joined portions in a desired orientation with respect to one another. Thus, the parts may move to a different, less than optimum, relationship after they have been installed on an engine.
Austrian Pat. No. 151,858, issued Dec. 10, 1937 to J. Heitmanek, discloses a pivot joint primarily for use for umbrellas, and the like, which is similar in nature to some of the embodiments of the aforementioned U.S. Pat. No. 3,354,419, but is provided with a detent for indexing the relative position of the two parts of the device and holding the relative moveable parts in a desired position. Spark plug connectors, however, are relatively small in size when compared to an umbrella, and the like, and it is apparent that a conventional detent arrangement as described in U.S. Pat. No. 3,354,419 would be too large for use with such a connector.
U.S. Pat. No. 1,989,893, issued Feb. 5, 1935, to J. Taylor, discloses ignition cable construction in which the spark plug receiving receptacle portion of the connector is pivotally mounted for movement through an arc of approximately 90.degree., and retained in predetermined positions by a plurality of notches arranged for retaining the receptacle portion of the connector in a desired position. Nevertheless, the construction as set forth in this patent permits only a relative few retaining notches to be provided, thus possibly limiting the applicability of the resulting connector.
U.S. Pat. No. 1,649,951, issued Nov. 22, 1927, to T. A. English, discloses an adjustable connection for brush handles, and the like, in which a pair of disc portions are pivotally joined to one another and one provided with a plurality of projections and the other with a matching number of depressions so as to permit indexing of the disc portions with respect to one another. Once again, as in the Austrian patent discussed above, where the indexing is accomplished by a detent either in the form of a biased ball or a generally hemispherical projection, the number of positions indexable in a comparatively small device such as a spark plug connector is extremely limited. U.S. Pat. No. 2,617,671, issued Nov. 11, 1962, to C. Barrango, on the other hand, discloses a pivot joint for use in manikins, and the like, which employs friction linings and plates to hold articulated portions of the manikin in a desired position. Once again, however, the relatively small size of a spark plug connector, however, particularly in comparison to the forces which can be applied to a connector, make it impractical to employ friction couplings to hold the parts of the connector in a desired orientation with respect to each other.
It is also desirable to provide spark plug connectors, and the like, with a cover or boot, an example of which is set forth in U.S. Pat. No. 2,943,139, issued June 28, 1960, to M. Skunda. Conventionally, these boots are formed in a predetermined internal angle as seen in the aforementioned U.S. patent, with U.S. Pat. No. 2,792,558, issued May 14, 1957, to R. C. Woofter, disclosing a spark plug boot having associated therewith a specially constructed terminal which permits a spark plug connector to be connected to a spark plug at an oblique angle while still disposed within a rigid boot. U.S. Pat. No. 2,665,673, issued Jan. 12, 1954, to R. C. Woofter, discloses a spark plug boot formed with a plurality of circumferential corregations permitting flexing of the boot to conform to the position of an ignition wire associated with the connector. This boot, however, does nothing to retain the wire and connector in a predetermined position relative to an associated spark plug.
Finally, British Pat. No. 16,828, issued June 13, 1912, to Longford, et al, discloses a spark plug receiving receptacle provided with a pin which can be inserted into the terminal end of an associated wire for connection of the receptacle to the wire. This construction, however, creates the additional problem or requiring one installing the set of spark plug wires to place the receptacle portion on the wire.